Male Infertility Causes

As nearly 50% of fertility problems in couples involve the male partner, the evaluation and treatment of the man is extremely important. Many of the causes of male infertility are treatable, and a careful history and physical exam will identify most of these causes. The most common cause of male infertility is the varicocele, the enlargement of the veins that normally surround the testicle. This problem may be identified in up to 40% of men presenting for male factor infertility evaluation. Other identifiable factors include blockages, hypogonadism (low hormones), problems with ejaculation, and gonadotoxins (exposure to substances harmful to the testes).

Treatment of these conditions often result in increased fertility, as evidenced by improved sperm counts and/or pregnancy.A patient’s medical history is an extremely crucial part of the fertility evaluation. Duration of infertility, previous pregnancies, and previous evaluation and/or treatment are key points. Sexual history, particularly with respect to potency and ejaculatory function, should be reviewed. Past medical history, including childhood and development, should be gathered. Specifically, any history of torsion (testicular twisting), cryptorchidism (undescended testes), or trauma in childhood may play a role in the cause.

Previous hernia repair may also cause blockages.Infections can affect fertility in several ways. Running a fever may periodically decrease sperm production, although this is usually short-lived. Mumps in adolescence may also cause problems with sperm production later in life. Sexually transmitted diseases, specifically Chlamydia and gonorrhea, may cause obstruction, as can any inflammatory condition within the testes or epididymides.

Gonadotoxins in the form of chemicals, medications (both prescription and over the counter), tobacco, alcohol, and illicit drugs, all affect sperm production to some degree. Finally, both family history and a physical examination may suggest a reason for the infertility. Other family members with fertility problems, or disorders such as cystic fibrosis or androgen receptor deficiency, all may suggest a genetic cause. Impaired visual fields, discharge from nipples, frequent respiratory infections, or problems with smell may also help identify both congenital (since birth) or acquired causes of infertility. Approximately 1% of men with subfertility have an underlying serious medical condition, such as a testis cancer or brain tumor which may contribute to the problem. Laboratory tests may also be used to make a diagnosis. All patients should have at least 2 semen samples analyzed.

There should be 2-5 days of ejaculatory abstinence before each sample is collected, and the samples should be collected 1-2 weeks apart. Because there is normal variation of sperm counts within an individual, if the 2 semen analyses are not similar, a third should be obtained. Although there are many characteristics that may be examined, the most important are the sperm density, motility (percent of moving sperm), volume and pH of ejaculate, quality of sperm movement, and the total number of motile sperm in the ejaculate. The treatment of male factor infertility is directed towards treating reversible causes, halting damaging factors, and assisting in advanced reproductive techniques. Varicoceles, dilated veins around the testicles, are the most common cause of male subfertility.

The success rate following treatment results in improvement in semen production in up to 70% of men, with 35-50% of the men being able to impregnate their partner.Obstruction of the ductal system is another treatable cause. This may be due to vasectomy, epididymal blockage from previous trauma or infection, congenital bilateral absence of the vas deferens, or previous surgery such as a hernia repair. Correction of obstruction, whether from vasectomy or other factors, results in return of sperm to the ejaculate in 50-95% of men. Pregnancy rates as high as 65-70% have been obtained, although a more realistic value is probably closer to 50%. It is possible to obtain sperm for freezing at the time of surgical correction; thus, if the procedure is not technically successful, the couple has frozen sperm that may be used in conjunction with in vitro fertilization.

Treatment of very low hormone levels (hypogonadism) typically results in moderate pregnancy rates, even when sperm counts do not improve dramatically. In the era of assisted reproductive technology, it is tempting to bypass evaluation of the male partner and proceed to more aggressive treatments, such as in vitro fertilization. However, this is a disservice to many couples, as identification and treatment of the male partner often results in pregnancy without other intervention, as well as correction of any underlying disorders.